'Your grandchild is such a cutie!' A passer-by said as she gushed at the infant in Grissom's arms.

'Thank you, but he's my son, not my grandson.'

'Oh, I'm so sorry,' the woman apologized and walked off hurriedly.

'And what do you think is so funny kiddo?' Grissom grumbled good-naturedly at his son, who was chuckling and patting his father's cheek enthusiastically, seemingly in agreement with whatever that had conspired earlier.

'What's so funny?' Catherine said as she and Lindsey came towards her husband and their son.

'Nothing.'

'And who was that lady you were talking to?' Catherine asked as she reached for her son.

'Just a woman who admired my cute "grandson".' Grissom said, frowning as Lindsey burst into a fit of giggles.

His wife was also trying unsuccessfully to hide her mirth by burying her face in her son's neck, but the occasional laugh still broke free.

'Glad you two think it's so funny.' Grissom grumbled.

'Sorry daddy, but it is funny.' Lindsey said with a smile, not looking the least bit sorry.

Grissom growled and picked the little girl up and spun her around before buckling her into the car.

Then he turned to his wife, who had a mischievous twinkle in her eyes.

She looked at him, then burst into a fit of giggles.

Grissom was not amused.

'I'm sorry, but I just. . . '

'I'll make you pay for that Catherine Grissom, just you wait!'

'I'm so sorry "grandpa Gil", please don't be mad!' Catherine teased.

'Grr . . .'

Before Grissom could get really worked up, Catherine leaned over and kissed him.

'Come on, let's go home. Maybe after the kids have gone to bed, you can show me that you're not that old after all. If you can manage to stay awake that is!'